I'd have to say no...I don't have the A700, but am familiar with it, and the sensor is quite good...and on the A5xx series cameras quite excellent, so low light/night shooting isn't any problem at all with these cameras. There are two very different forms of low light shooting - handheld high ISO shooting, and tripod mounted long-exposure shooting. I do both types of photography, and heavy use of the Sony 18-250mm lens as well. I also have the Minolta 50mm F1.7, and use my Tamron 10-24mm ultrawide and Sigma 30mm F1.4 for low light work often too.

Night photography is one of my specialties, a favorite type of shooting along with wildlife/birding. For a browse of all my night photography styles with my A550 and many different lenses, including many shots from the 18-250mm lens:
http://www.pbase.com/zackiedawg/night_p ... y&page=all

Night photography definitely requires some technique and some practice. First off, the sharper results will come from using low ISO and long exposures on a tripod - that's with any lens. For sharp results handheld, the biggest issue to overcome is the need for very fast apertures (like your 50mm F1.4)...two problems arise - often these fast lenses are not at their very sharpest when used wide open, and are better when stopped down just a bit; and the depth of field becomes so shallow when shooting fast apertures that focus is critical to nail, and softness/blur sets in just inches off the focus point. This can be a desirable thing too - taking advantage of the shallow depth of field for those nice, soft blurred backgrounds...but can also render what appears to be a soft or out-of-focus image.

Your A700 should be more than capable of shooting handheld night shots at ISO3200 with a little cleanup of noise in post-processing, or ISO1600 straight from the camera. With the F1.4 lens at these sensitivities, that should give you the ability to shoot in extreme dark conditions. If you use long exposures and a tripod, your camera should become excellent, sharp, detailed, and noise-free by lowering the ISO, stopping down the aperture, using mirror-lock-up, and the self-timer on a tripod.

I did many night shots with A700 and Tamron 18-250. With ISO 100 and long exposures the results are quite good. The dissatisfaction I have is with normal shots at ISO 400 +. The noise becomes quite visible even affecting the sharpness. The problem aggravates more at night. Maybe this pertains to my particular camera, I don't know. Before I upgraded to A700 I thought I should not have any issues with A700 up to ISO 1600. But seems like I had too high expectations. A700 still a great camera though, dynamic range and color capture is much better than on A200, I am just now trying to use the lowest ISO as possible all the time.

hey! guys! thanks for all your reply... and my prob is the handheld... 50mm1.4 is quite cool but not that wide... its my best lens for low light but still not really fan of prime. love some flexibility...

18-250 is really freaking me if i zoom in... but i figure out how to manage those problem w/ a flash but sometime we like to do some no flash photos'

Your camera has been improved upon with later Sony models for high ISO shooting, but you should still be able to get something usable at ISO1600 and maybe ISO3200 if you get a simple noise reduction software, even with the 18-250mm lens.

I do quite a bit of handheld high ISO shooting with my 18-250mm lens on my A550 - while my high ISO performance is a little better than your A700, it still is more a matter of getting the right exposure, and knowing how to keep a steady stance using stabilization to get slower shutter speeds without blur. Just through technique and practice, with steadyshot on, I can handhold regularly at shutter speeds to as long as 1/2 second. That lets me get handheld shots even with fairly slow lenses like the 18-250.

Handheld ISO3200 at night, with a 1/8 shutter, using the 18-250mm lens:

ISO3200 handheld again with the 18-250mm lens, at 1/30 taken from a moving boat:

Of course, a fast prime lens would do even better - if you enjoy the types of shots you can get from your 50mm F1.4 but want wider, I can recommend the Sigma 30mm F1.4 lens as an excellent, sharp performer.